I'm using the Google Visualization API to generate some charts on a webpage and want to make use of the 'Explorer' option to allow users to zoom in on areas of Line Charts.

The charts are working fine (see fiddle below) but I'd like to change the highlight color of the box created when dragging to zoom. The default is a very distinctive Google-ish Blue:

I've currently set the parameters of the Explorer object as detailed below, but the "Line Chart Reference" doesn't mention a property that can be set to change the highlight color, so how might I go about doing it? I tried delving into the 'loader.js' file but couldn't make any sense of what it was doing! Many thanks.

I may have jumped the gun on the last update, it seems as though Mutation Events such as DOMNodeInserted have been deprecated for a while due to performance issues, so I've rewritten my previous solution using the more widely supported MutationObserver as shown below.